I have one N95 mask (a few years old) that I've used a few times

[LuckyCharms]

to protect from sawdust while sanding.

Does anyone know if it still offers protection virus protection?

If I were to wear it now in public, can I reuse it after that?

I'd donate it to a medical professional, but it is kind of grimy from my previous use.

Thank you.

[Vinca]

1. We've got 3 or 4 previously worn N95 masks, too (drywall projects). I guess we'd use

them in a pinch, but the general guideline now is that unless you, yourself, are ill, it's not necessary to wear a mask. I've read about medical people drenching their masks in hand sanitizer for reuse and it doesn't sound like they feel all that confident that they won't spread infection around by wearing them multiple times. We bought a box of less effective masks off ebay just in case, but I anticipate they'll end up being used for home projects rather than to protect from the virus.

[LisaL]

2. And how would you know if you are ill?

Some (quite a bit) of people with covid are asymptomatic. Furthermore it can spread even before someone starts showing symptoms.

[Vinca]

3. Good question and way above my pay grade.

[LuckyCharms]

4. Thanks, Vinca. I need to go to the pharmacy which is within

a huge grocery store to pick up a bunch of prescriptions. I'm at very high risk if I get the virus. I've been getting groceries delivered, but they will not deliver the prescriptions.

My plan was to wear the mask, safety goggles, and gloves when I picked them up. I would then discard the gloves in the breezeway trash can outside the store before I got back into my car so as to not contaminate my steering wheel. Then, I'd enter back into my house through my garage, dispose of the paperwork etc. that comes with the prescriptions, sanitize the prescription bottles with clorox wipes in garage, strip naked and throw clothes in washer in garage, wash hands in garage, and then go in the house and take a shower.

Sheesh! I am probably being paranoid, but better safe than sorry I guess.

Stay safe, Vinca.

[LisaL]

9. Bake your mask in the oven for 30 minutes at 158 degrees Fahrenheit.

From the link posted on the thread, it seems to be effective and still keeps integrity of the mask.

[Silver Gaia]

16. That sounds like a very good plan to me.

That's pretty much what I've been doing. There's no such thing as too much caution right now. My theory is same as yours: better safe than sorry. Don't think of yourself as paranoid. You are just being careful.

[Vinca]

17. You stay safe, too. We have to keep telling ourselves this shall eventually pass.

I wipe my hands and car handles and steering wheel and controls multiple times when I have to go out. I found some Lysol wipes on the local Walmart web site at 7 a.m. this morning and raced over because we need more and "supplies were limited." I was happy to see they had a young clerk stationed at the self checkout with cleaning supplies and she wiped everything down between customers checking out. There weren't that many people out and about at that time of day so I guess that's my new plan when I have to go out: fast trips early. I did exactly what you did when I got home. Stripped, put the clothes in the washer and jumped in the shower. Nothing like a 71 year old woman streaking through the house to the bath. LOL.

[Doremus]

5. If you don't have a new mask replacement, you can disinfect used ones.

Referring to a paper published in the journal Annals of Occupational Hygiene in 2009, among others, the researchers compared and contrasted these different methods for sterilizing N95 masks, many of which were ineffective:

Heat in an oven for 30 minutes at 58 degrees Fahrenheit (70 degrees Celsius)
Use ultraviolet light for 30 minutes
Soak the mask in 75% ethyl alcohol, then let it dry
Clean the mask with liquid or vapor hydrogen peroxide
Clean the mask with bleach
Steam the mask with hot vapor from boiling water
Microwave the mask
Use extreme heat in an oven or autoclave
Soak in soap and water

"To be useful, a decontamination method must eliminate the viral threat, be harmless to end-users and retain respirator integrity," they wrote.

All of the methods used were believed effective for destroying coronaviruses, they wrote, but not all of them were good ideas.

"DO NOT use alcohol and chlorine [bleach]-based disinfection methods," they wrote. "These will remove the static charge in the microfibers in N95 facial masks, reducing filtration efficiency. In addition, chlorine also retains gas after de-contamination, and these fumes may be harmful."

Microwaves tended to melt the masks and render them useless.

Hydrogen peroxide and ultraviolet radiation appeared to be at least somewhat more effective, they wrote, "but it is not known if they would retain filtration, material strength and airflow integrity with repeated use."

Autoclaves, 320 F [160 C] ovens, and soap and water soaking, all appeared ineffective, they wrote.

However, they wrote, "70 C / 158 F heating in a kitchen-type of oven for 30 min, or hot water vapor from boiling water for 10 min, are additional effective decontamination methods."

https://www.livescience.com/sanitizing-medical-masks-for-reuse-coronavirus.html

[LisaL]

7. 70 degrees Celsius is 158 degrees Fahrenheit.

[LuckyCharms]

10. Thanks very much. I'll try the hot water vapor. That seems least likely

to damage the rubber band-like straps (but those may be removable, I'll have to check).

[CrispyQ]

6. I read that anything is better than no mask, even a bandanna. ???

Some links for DIY solutions that may be helpful:

Simple Respiratory Mask: https://www.democraticunderground.com/100213130867

DIY face mask: https://jennifermaker.com/face-mask-patterns-cricut/

There are a ton of patterns out there. Just google "DIY face mask pattern."

What Are The Best Materials for Making DIY Masks?: https://smartairfilters.com/en/blog/best-materials-make-diy-face-mask-virus/

[unblock]

8. from what i can gather, there are several issues

overall, it's likely better than nothing; that said, you shouldn't over-rely on it protecting you.


first, fit is important. this can be a challenge even with brand new masks, especially with facial hair or particular facial contours. older masks may not be as flexible.

second, there are apparently slightly different masks, approved by different federal agencies. your sawdust mask was probably ohsa-approved, and ideally you want the chc-niosh-approved masks. i'm not sure there's a material difference in the masks themselves, it may only be the approval process that's different, just something to consider.

finally, the question of reuse. it it's just sawdust, i don't see why it wouldn't still be effective as is, or if you blew out some of the sawdust. other have noted that even health professionals have reused theirs, trying to sanitize them between uses. needless to say this is all less than ideal.

[LuckyCharms]

13. You bring up a good point about facial hair.

I have a pretty thick beard, so this is an issue for me.

Your post just made me recall a conversation I had with a cardiologist who was also a volunteer fireman. He pointed out that while you see many fireman with mustaches, you don't see any with full beards because that facial hair interferes with the masks they wear when they go inside burning structures.

[FarPoint]

11. It is better than nothing....

Try and reinforce it with the home made surgical masks/ layers...face shield may help....We are on our own...

[LisaL]

12. I think N95 mask should go on first, and homemade or surgical goes on top of it, to protect N95.

But it would make it very hard to breathe.

[LuckyCharms]

14. I had thought of using the mask covered with a

doubled over bandanna. I'll get very little air to breathe, but my goal would be to go at a non-busy time, and try to get the heck out of there in about 3 minutes.

[marybourg]

15. You can hope. I went to my cvs the other nite,

There were only four customers in the whole store. Only one at the pharmacy counter. There were four pharmacists/techs behind the counter. Only one came and went to the register area. It took 20 minutes to get out of there.